Hierarchical Planning Algorithm for Redundant Mobile Manipulators to Follow a Given Trajectory

Abstract

This paper presents a hierarchical planning algorithm for redundant mobile manipulators to follow a given trajectory. It can guarantee the manipulation capability of the manipulator and optimize the movement of the base. Firstly, we analyzed the distribution of the manipulability measure of the manipulator and adopted polynomials to fit the boundary of the feasible workspace in which the corresponding manipulability is greater than a threshold value. Then for each point in the trajectory, the feasible area of the base is determined. We adopted the dynamic programming (DP) method to compute an initial path of the base and the gradient descent (GD) method to optimize the initial path. Finally, we recompute the joint configuration of the manipulator. The simulation and experiment results verified the feasibility and effectiveness of the proposed algorithm and the movements of the base and manipulator are stable and continuous.